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6.6L gasser MPG with new 10 speed Allison tranmission?

campah

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in 6.6L Gas V8 (L8T)

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Jim-GA Enthusiast

Jim-GA

Posted
Posted
On 12/20/2023 at 5:19 PM, Jettech1 said:

And why that is who knows.... different tire sizes maybe?

Well... stock factory tires. All stock. An error of 11% is kind of high to me.

 

And of course it is an error to make the truck MPG look better than it really is. If the computer were reporting 11% lower than actual values, GM would demand their engineers fix it, to not make the truck look bad. 

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kylant
kylant

sorry man. lofty expectations that are not going to be realized

the8rotor
the8rotor

Gas mileage is the same between 6L90 and 10speed, I've had both. I get anywhere between 11-13.5mpgs city and 18/19mpgs highway ripping around the toll roads in Texas.    Towing my 10-12k cam

UWSkier
UWSkier

I did a freeway run this morning in my truck too.  10 speed 6.6, speeds 75 to 80 mph.  Best 25 mile stretch was 19.3 but I got 18.4 over the 160 mile round trip, verified at the pump.  It was my first

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Jettech1 Senior Enthusiast

Jettech1

Posted
Posted
On 12/21/2023 at 11:34 PM, Jim-GA said:

Well... stock factory tires. All stock. An error of 11% is kind of high to me.

 

And of course it is an error to make the truck MPG look better than it really is. If the computer were reporting 11% lower than actual values, GM would demand their engineers fix it, to not make the truck look bad. 

At least you get to live in the North GA mountains.  I have to live near Atlanta due to my job.  I would love to live up there!!  We will be heading to the Cherokee Campground soon for a few days.  I can't wait.  I have an aunt and uncle that live in Demorest too.  To live up there....I'm green with envy!!!  Enjoy sir!!!

  • 2 weeks later...
Jettech1 Senior Enthusiast

Jettech1

Posted
Posted
6 hours ago, Truston Gunter said:

my MPG info/history

Screenshot 2024-01-10 132038.png

Screenshot 2024-01-10 132046.png

Screenshot 2024-01-10 132051.png

Great records.  You filled up 7 times on 11/26/21?  Don't you ever sleep? LOL

Pryme Senior Enthusiast

Pryme

Posted
Posted
40 minutes ago, Jettech1 said:

Great records.  You filled up 7 times on 11/26/21?  Don't you ever sleep? LOL

Yeah like 1,100 miles. It’s doable. I made the twin cities to Vegas in 24hrs. That was in a sedan and not pulling a trailer though. And I was movin at a pretty little clip

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Jettech1 Senior Enthusiast

Jettech1

Posted
Posted (edited)
47 minutes ago, Pryme said:

Yeah like 1,100 miles. It’s doable. I made the twin cities to Vegas in 24hrs. That was in a sedan and not pulling a trailer though. And I was movin at a pretty little clip

True, reminds me of my trips to Maine from Atlanta I used to do back in the early 2000's.  I had a 95 E320 that I used to drive up there to take my mother to chemo treatments, then generally I would just leave it there for her to use because she had this old clapped out rusted chevy cavalier.  I would fly back to Atlanta for a couple of weeks, then fly back up there to take her for more chemo.  Then if she had a month or so off from chemo I would drive it back to Atlanta.  Anyhow I did that trip so many times I lost count and would do it all in one shot.  1300 miles.  Used to take me anywhere from 19 to 21 hours depending on how lucky I felt going through Virginia....lol....they don't mess around when it comes to speeding and radar detectors are illegal there.  And to this day they use old Impalas to catch people speeding.  A total no fun state...lol....It's funny look back on those days at times, I offered to give it to her, it was an amazing car for sure.  But no, she had too much of that Mainer pride in her.  God rest her soul....

Edited by Jettech1
  • Like 1
Pryme Senior Enthusiast

Pryme

Posted
Posted
8 hours ago, Jettech1 said:

True, reminds me of my trips to Maine from Atlanta I used to do back in the early 2000's.  I had a 95 E320 that I used to drive up there to take my mother to chemo treatments, then generally I would just leave it there for her to use because she had this old clapped out rusted chevy cavalier.  I would fly back to Atlanta for a couple of weeks, then fly back up there to take her for more chemo.  Then if she had a month or so off from chemo I would drive it back to Atlanta.  Anyhow I did that trip so many times I lost count and would do it all in one shot.  1300 miles.  Used to take me anywhere from 19 to 21 hours depending on how lucky I felt going through Virginia....lol....they don't mess around when it comes to speeding and radar detectors are illegal there.  And to this day they use old Impalas to catch people speeding.  A total no fun state...lol....It's funny look back on those days at times, I offered to give it to her, it was an amazing car for sure.  But no, she had too much of that Mainer pride in her.  God rest her soul....

Sounds like a very hard period of time for you both. I bet she was appreciative of that level of support you gave her during that time. 

  • Like 1
KARNUT Senior Enthusiast

KARNUT

Posted
Posted
8 hours ago, Jettech1 said:

True, reminds me of my trips to Maine from Atlanta I used to do back in the early 2000's.  I had a 95 E320 that I used to drive up there to take my mother to chemo treatments, then generally I would just leave it there for her to use because she had this old clapped out rusted chevy cavalier.  I would fly back to Atlanta for a couple of weeks, then fly back up there to take her for more chemo.  Then if she had a month or so off from chemo I would drive it back to Atlanta.  Anyhow I did that trip so many times I lost count and would do it all in one shot.  1300 miles.  Used to take me anywhere from 19 to 21 hours depending on how lucky I felt going through Virginia....lol....they don't mess around when it comes to speeding and radar detectors are illegal there.  And to this day they use old Impalas to catch people speeding.  A total no fun state...lol....It's funny look back on those days at times, I offered to give it to her, it was an amazing car for sure.  But no, she had too much of that Mainer pride in her.  God rest her soul....

In the mid 90s I traveled through Virginia a lot going to New Jersey. I got stopped a few times just because I was driving my 1 ton dually. They would ask why I was driving a truck. They did it with my father too. He going to visit my grandparents. What do you mean I would ask. They would go through my toolbox and cooler in the bed. The 100 gallon fuel tank would raise suspicion. I would reply you don’t have people who work from pickups in your state? In Texas trucks were usually pretty fancy and were noisy. They never gave me a reason, just harassment. I left my radar detector once on the dash unplugged. A cop actually saw it and came after me. I either had to hand it over or get a ticket. He wouldn’t listen to it was disabled. My father’s Texas stadgecoast came with a built in above his head. In the oven head console. His first trip to New Jersey they stopped him. That truck was really fancy. Fender Flairs that ran into running boards. They saw it, made him pull it out. Same thing what you doing here in that truck? My mom was with him. She told him, just driving through. 

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Pryme Senior Enthusiast

Pryme

Posted
Posted
3 minutes ago, KARNUT said:

In the mid 90s I traveled through Virginia a lot going to New Jersey. I got stopped a few times just because I was driving my 1 ton dually. They would ask why I was driving a truck. They did it with my father too. He going to visit my grandparents. What do you mean I would ask. They would go through my toolbox and cooler in the bed. The 100 gallon fuel tank would raise suspicion. I would reply you don’t have people who work from pickups in your state? In Texas trucks were usually pretty fancy and were noisy. They never gave me a reason, just harassment. I left my radar detector once on the dash unplugged. A cop actually saw it and came after me. I either had to hand it over or get a ticket. He wouldn’t listen to it was disabled. My father’s Texas stadgecoast came with a built in above his head. In the oven head console. His first trip to New Jersey they stopped him. That truck was really fancy. Fender Flairs that ran into running boards. They saw it, made him pull it out. Same thing what you doing here in that truck? My mom was with him. She told him, just driving through. 

Sounds like a nightmare. Never had any desire to visit jersey or Virginia and now I have even less. 

  • Like 1
KARNUT Senior Enthusiast

KARNUT

Posted
Posted
1 minute ago, Pryme said:

Sounds like a nightmare. Never had any desire to visit jersey or Virginia and now I have even less. 

I grew up in New Jersey, I don’t miss anything there.

  • Like 2
Truston Gunter Enthusiast

Truston Gunter

Posted
Posted

That was our trip to the hills of Tennessee!!! Long haul with the camper and 2 kids! Had to be back at work on Monday after Thanksgiving so it was a short stay. I find myself truly enjoying these road trips! Awesome family memories and hopefully many more to come!!!!!

  • Like 1
  • 2 months later...
BCGM Enthusiast

BCGM

Posted
Posted (edited)

I think I asked this question on another thread but what is the difference in MPG between a 2500 HD and 3500 HD ? I would think the 3500 would get less as its a heavier truck Also how much of a difference is there in MPG with the 20 inch wheels and tires Versus the 18 inch wheels and tires ?

Thank You 

Edited by BCGM
Pryme Senior Enthusiast

Pryme

Posted
Posted
21 hours ago, BCGM said:

I think I asked this question on another thread but what is the difference in MPG between a 2500 HD and 3500 HD ? I would think the 3500 would get less as its a heavier truck Also how much of a difference is there in MPG with the 20 inch wheels and tires Versus the 18 inch wheels and tires ?

Thank You 

Yes, everyone said none. No discernible difference. 

MORSNO Enthusiast

MORSNO

Posted
Posted
21 hours ago, BCGM said:

I think I asked this question on another thread but what is the difference in MPG between a 2500 HD and 3500 HD ? I would think the 3500 would get less as its a heavier truck Also how much of a difference is there in MPG with the 20 inch wheels and tires Versus the 18 inch wheels and tires ?

Thank You 

 

The weight difference is very little, same frame, body, engine, transmission.  The rear axle and the F/R springs are slightly different that's about it.  The 18" and 20" wheels have tires with the same circumference with small wheel and tire weight differences and with the two stock size tires for my truck, the 18" has a couple hundred pounds heavier load capacity (124 vs 121).

Another JR Senior Enthusiast

Another JR

Posted
Posted

The relevant differences, if any, on an unloaded 2500 vs 3500, are going to be tires, suspension lift, and whether you have the antler-style towing mirrors, which add a square foot of  frontal area. 

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